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New heat pump system

Hi everybody,

it's the common question here: what heat pump system to get. We have a 2400sqf two-story house in Maryland, northeast of Baltimore. No shade and southern exposure, but I sealed the duct trunk in the (unfinished, fullsize) basement and return "ducts" (no sheet metal, just drywall and framing), airsealed the basement and the attic quite well and added a good amount of insulation into the attic (which has saved us already considerable amounts of money on our energy bills). Manual J calculations will be done according to one of the contractors visiting so far, as required by the county (is block house load calculation the same?). We haven't received his estimate/recommendation yet. After reading many posts here in this forum, we lean towards the Trane XL20i with matching air handler. Any reason not to go with that over a XL15i or XR16? The XL20i is the only two compressor system which gives it a slight advantage, short of the Carrier Greenspeed. What the difference between the TAM7 and TAM8 airhandlers? The Trane website is short of information on that. Any recommendations for a thermostat and media filter cabinet? We'd like on-demand dehumidification, which why we don't consider the XL16i. Recommendations/thoughts with regards to a whole-house humidifier? What about Carrier? I know they don't have on-demand defrost which might me quite important in our climate. No Rheem/Ruud dealers in the area, and not too many York either. Does York have anything comparable to the the XL20i or other features that might be important to consider. I tried to read as much as I could and I know some of these questions are redundant but the search feature gets you only so far.

Discounting the Carrier Greenspeed/Bryant Extreme HP IMO is a mistake when primarily heating with a HP. Why? Because if you address both the load needed and the duct layout, it may be possible to install a LARGER unit giving you the advantage of useful Btu's from the HP to much lower outdoor temperatures, thus requiring less use of aux heaters. Also, if you check the efficiency of those units, you'll find them among the highest and thus lower operating costs still. Those variable speed outdoor units, which ramp down to 30% of full capacity, can also do an excellent job in the summer, even though they're over sized for heating advantage. The reason they're so good at summer cooling as well is their ability to ramp down to the exact capacity needed for any given outdoor ambient and humidity condition. Depending on the actual size installed, you could see SEER/EER/HSPF values of 20.5/15.7/12.5, all of which are exceptionally high. Heating your home on a cold winter day with 12.5 HSPF is way more energy efficient than heating with electric resistance at a value of 1.0. I think you're doing yourself a disservice by not thoroughly investigating and understanding the value of modulating heat pumps at this juncture. They're the wave of the future and here now.

If YOU want change, YOU have to first change.

If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

it's the common question here: what heat pump system to get. We have a 2400sqf two-story house in Maryland, northeast of Baltimore. No shade and southern exposure, but I sealed the duct trunk in the (unfinished, fullsize) basement and return "ducts" (no sheet metal, just drywall and framing), airsealed the basement and the attic quite well and added a good amount of insulation into the attic (which has saved us already considerable amounts of money on our energy bills). Manual J calculations will be done according to one of the contractors visiting so far, as required by the county (is block house load calculation the same?). We haven't received his estimate/recommendation yet. After reading many posts here in this forum, we lean towards the Trane XL20i with matching air handler. Any reason not to go with that over a XL15i or XR16? The XL20i is the only two compressor system which gives it a slight advantage, short of the Carrier Greenspeed. What the difference between the TAM7 and TAM8 airhandlers? The Trane website is short of information on that. Any recommendations for a thermostat and media filter cabinet? We'd like on-demand dehumidification, which why we don't consider the XL16i. Recommendations/thoughts with regards to a whole-house humidifier? What about Carrier? I know they don't have on-demand defrost which might me quite important in our climate. No Rheem/Ruud dealers in the area, and not too many York either. Does York have anything comparable to the the XL20i or other features that might be important to consider. I tried to read as much as I could and I know some of these questions are redundant but the search feature gets you only so far.

Thanks.

Klaus

First start with a contractor that completes a Manual J 8 on your home this will determine what type of equipment is needed, depending on the latent and sensible load. If your system is sized properly you should not need dehumidify on demand. The same goes for a humidifier if there is not an air infiltration issue with the home a humidifier is not nessecary, human activities will create enough moisture under normal conditions.

You want a room by room load calculation not a block load. This will allow the contractor to determine how many CFM is needed for each room. Post your actual location, there are several good companies on this sight above Baltimore.

Discounting the Carrier Greenspeed/Bryant Extreme HP IMO is a mistake when primarily heating with a HP. Why? Because if you address both the load needed and the duct layout, it may be possible to install a LARGER unit giving you the advantage of useful Btu's from the HP to much lower outdoor temperatures, thus requiring less use of aux heaters. Also, if you check the efficiency of those units, you'll find them among the highest and thus lower operating costs still. Those variable speed outdoor units, which ramp down to 30% of full capacity, can also do an excellent job in the summer, even though they're over sized for heating advantage. The reason they're so good at summer cooling as well is their ability to ramp down to the exact capacity needed for any given outdoor ambient and humidity condition. Depending on the actual size installed, you could see SEER/EER/HSPF values of 20.5/15.7/12.5, all of which are exceptionally high. Heating your home on a cold winter day with 12.5 HSPF is way more energy efficient than heating with electric resistance at a value of 1.0. I think you're doing yourself a disservice by not thoroughly investigating and understanding the value of modulating heat pumps at this juncture. They're the wave of the future and here now.

Thanks for the insights. And we haven't excluded the Greenspeed which was actually quite high on our list because of the inverter compressor (and we'll ask for quotes) but two of the contractors I spoke with said we would never save enough with this unit to make up for the price premium it still commands as of now. How much of a difference does the lack of on-demand-defrost on this unit make in the overall efficiency during heating? How much energy is lost because of unneccessary defrost cycles over the lifetime and how does that impact the heating efficiency? What do you think?

Thanks for the insights. And we haven't excluded the Greenspeed which was actually quite high on our list because of the inverter compressor (and we'll ask for quotes) but two of the contractors I spoke with said we would never save enough with this unit to make up for the price premium it still commands as of now. How much of a difference does the lack of on-demand-defrost on this unit make in the overall efficiency during heating? How much energy is lost because of unneccessary defrost cycles over the lifetime and how does that impact the heating efficiency? What do you think?

Why is it that with our business everyone is worried about a "payback". Don't get me wrong, efficiency should be high on the list, but.............do you drive a Yugo or a Mercedes? Both will do the job of getting you from point A to point B.

Sometimes, in our business, people want the best comfort. Comfort: even temperatures and quiet operation.

I know of a couple that built a home and they wanted the latest and greatest geothermal system. Unfortunately, it was installed incorrectly and they could not cool the second floor...........they sold the home. Comfort is much more important than price is my point.

There are numerous posts listed here where people are have problems with comfort issues.........I haven't read any that brag about how much they are saving........that's icing on the cake, IMHO.

George, I drive neither a Yugo nor a Mercedes. Do you only install Carrier Greenspeed systems? Life is mostly a compromise, isn't it? We could also move to a different climate, new house etc., Don't get me wrong, I value your and everybody else’s input, but would you be so kind to explain what the Greenspeed system gains us in term of comfort over say the Trane XL20i with VS air handler if the sized correctly? If sized correctly, and you define comfort as even temperatures and quite operation, I fail to see the difference between the system when it comes to comfort. I did a lot of reading here on this site and when it comes to cooling what kind of comfort difference could I expect? Now the Greenspeed is substantially more efficient at heating, but my legitimate question would be how does the lack of on-demand defrost effect that efficiency? Educated guess is fine, if you or skippedover or second opinion want to take a stab at it. And what is the increased comfort level gained by using the Greenspeed in heating? If the air still gets dry enough in the winter wouldn't a humidifier gain you more comfort with either system? I'd really like to know what I am missing. I don't want to brag how much I save (or how much I spent), but for us money spent on something that is quantifiable in some way, we'd say it might be better spent on something else, retirement, college for grandchildren etc. As far as I can see, Greenspeed type of technology is the way to go in general, but who knows what we'll have in 15 years from now.

Second opinion, we're located in Forest Hill, MD just north of Bel Air. Looked at the directory here and could only find one contractor located in Baltimore. Not sure he serves our county. We will ask specifically for a room by room Manual J to determine the correct size.

George, I drive neither a Yugo nor a Mercedes. Do you only install Carrier Greenspeed systems? Life is mostly a compromise, isn't it? We could also move to a different climate, new house etc., Don't get me wrong, I value your and everybody else’s input, but would you be so kind to explain what the Greenspeed system gains us in term of comfort over say the Trane XL20i with VS air handler if the sized correctly? If sized correctly, and you define comfort as even temperatures and quite operation, I fail to see the difference between the system when it comes to comfort. I did a lot of reading here on this site and when it comes to cooling what kind of comfort difference could I expect? Now the Greenspeed is substantially more efficient at heating, but my legitimate question would be how does the lack of on-demand defrost effect that efficiency? Educated guess is fine, if you or skippedover or second opinion want to take a stab at it. And what is the increased comfort level gained by using the Greenspeed in heating? If the air still gets dry enough in the winter wouldn't a humidifier gain you more comfort with either system? I'd really like to know what I am missing. I don't want to brag how much I save (or how much I spent), but for us money spent on something that is quantifiable in some way, we'd say it might be better spent on something else, retirement, college for grandchildren etc. As far as I can see, Greenspeed type of technology is the way to go in general, but who knows what we'll have in 15 years from now.

Second opinion, we're located in Forest Hill, MD just north of Bel Air. Looked at the directory here and could only find one contractor located in Baltimore. Not sure he serves our county. We will ask specifically for a room by room Manual J to determine the correct size.

Thanks.

Klaus

I sent a PM to one of the dealers up there that might be close enough. Carriers defrost cycle on the Greenspeed and Infinity mirrors on demand defrost by Trane Not enough to notice the difference if the system is sized and installed correctly.

The location of the OD unit can have an effect on the defrost cycle along with indoor airflow and return air temperature. The Greenspeed works well but are quite expensive at this point in time, and if a dealer is not proficient with all aspects of our industry that is a lot of money to put on the line with a high probability of failure.

And a lot of the blame can be put on the manufactures that want to move boxes and not requiring a dealer to be proficient before being allowed to represent a product, and this is not brand specific.

I agree life is about compromise and priorities. I'm just saying don't rule out the Greenspeed because of the price.

No matter what you decide, you'll eventually get used to it, good or bad. But it is something you'll have to live with, possibly for a long time. Or, you could sell your home, as in the example I gave.